Motors having stators and rotors energized by the stators to rotate a rotor shaft are well known in the art. In a typical construction, the stator of the motor is supported by the housing, and the rotor core extends through the cylindrical inner extent of the stator for rotation relative to the stator when electrical energy is applied to the motor. A rotor shaft secured to the rotor core is rotated by the rotor core, and attached to a driven element for operation of the latter.
In present motor units, bearing elements are applied between the motor housing and the rotor shaft, usually at the points where the rotor shaft extends out of the stator and the rotor core. The bearing elements usually provide the only means of supporting the combined rotor core and rotor shaft, with no support internal of the stator-rotor core combination. If additional support for the rotor shaft is required, it is provided in the form of additional bearing elements positioned along the portion of the rotor shaft which extends out of and away from the rotor core. This necessitates motor housings requiring extra length to accommodate the additional bearing elements.
If additional bearings are not used because of a lack of space in the motor housing, the support elements for the drive shaft provide reduced strength, thereby decreasing the torque capability and efficiency of the motor. Also, heavier rotor shafts must be used to compensate for decreased bearing support.
Therefore, a primary object of the present invention is to provide a novel motor and motor housing construction which provides bearing support for the rotor shaft and rotor core which delivers added torque capability and increased efficiency of the motor.
Another object of the present invention is to provide a novel motor and motor housing construction which provides added bearing strength for the rotor shaft, thus allowing the use of a relatively smaller drive shaft for the motor.
A further object of the present invention is to provide a novel motor and motor housing construction which permits a relatively compact, shorter motor package.
Yet another object of the present invention is to provide a novel motor and motor housing construction which decreases the moment arm acting on the bearing system and on the rotor shaft, and reduces the moments along the length of the shaft.
Still another object of the present invention is to provide a novel motor and motor housing construction which permits the rotor shaft to rotate with less wobble by securing added alignment strength as a result of permitting use of a shorter rotor shaft.